Too many students in high-poverty, urban communities drop out of high school, and too few graduate prepared for college and careers. Three national organizations--Talent Development Secondary, City Year, and Communities In Schools--have formed Diplomas Now in an effort to transform urban secondary schools so fewer students drop out and more graduate ready for postsecondary education and work. Thanks to a validation grant from the U.S. Department of Education's 2010 Investing in Innovation (i3) competition and matching funds from private sources, teams from all three organizations are implementing the Diplomas Now data-driven, tiered intervention model in schools across the nation. The model combines a comprehensive school reform strategy aimed at transforming the academic experience of all students with early warning indicators related to attendance, behavior, and course performance. Diplomas Now identifies students at risk of dropping out and intervenes with targeted support intended to get failing students back on track. MDRC and ICF International are conducting an independent, experimental evaluation of the impact and implementation of Diplomas Now. During the 2011-2012 and 2012-2013 school years, 62 secondary schools in 11 school districts agreed to participate in this study. Thirty-two of these schools were randomly assigned to implement the Diplomas Now model while the other 30 schools were assigned to a "control group," continuing their existing school programs or implementing other reform strategies of the districts' or schools' choosing. This report introduces Diplomas Now and the associated evaluation, describing the reform model, the research design, and the participating schools and districts. The report also shares first-year implementation fidelity findings, and discusses collaboration among the Diplomas Now partners and between those partners and schools. Appendices include: (1) Baseline Administrator and Teacher Survey Response Rates and Measure Creation; (2) Program and School Staff Survey Response Rates and Fidelity Matrix; and (3) Interview and Focus-Group Response Rates and Case-Study Methodology.